CompuServe Messages

Jon, Coal rank is more a function of coal age, more than purity. The ranking system is based on carbon content for the higher ranked coals, and BTU for the lower ranked coals. The older coals have had more time to undergo coalification, thus has had more of the water squeezed out. The lower rank coals in the west are known for their low sulfur content. Generally western coals have less sulfur, while eastern are typically higher. For all practicle purposes the Illinois coal basin coal have the highest sulfur content. These coals include Illinois, Indiana, and Western Kentucky. There are alot of low sulfur eastern coal reserves as well, but as they are typically more expensive to mine, thus western coals are prefered cost wise. Lower ranked coals normally contain more moisture, and less BTU's than higher ranked coals. As the moisture is locked into the structure, it cannot be romoved, so when transported you are shipping less coal than if you had a higher ranked coal. Ash, the unwanted parts of coal varies from coal to coal. Higher ranked coal can be just as high in ash as lower ranked coals. Ash can be cleaned out of a coal to a limited extent. Often this cleaning will take out some of the sulfur. This activity is called coal preparation, and is an important activity in some coal mining operations. Steve Brooks